Ecological distribution and population features of Hexapanopeus paulensis Rathbun, Crustacea: Decapoda: Xanthoidea caught by bottom trawling in the southeastern coast of Brazil: implications for its population structure. Instituto de Biologia - Campus Umuarama. Estrada do Bem Querer, km Rua Nelson Bhihi Badur, Estrada Odovaldo Novo, km
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Nutr Hosp. Intestinal microbiota; relevance to obesity and modulation by prebiotics andprobiotics. Introduction: The intestinal microbiota has several beneficial functions related to host health. Studies suggest that it may be related to the presence of metabolic dise- ases, including obesity. Objective: A bibliographic survey was carried out upon the relationship between the intestinal microbiota and obesity and the possible impacts of the use of prebiotics and probiotics, aiming to understand this complex and promi- sing interaction.
Results and discussion: We identified original studies. After careful selection, 61 original articles were included in this review. The others indicated that there are differences in the microbial composition between obese and non-obese patients and the possible mecha- nisms involved. Alteration is caused in the energy home- ostasis, in the use of dietary intake and storage of lipids due to the composition of the intestinal microbiota.
Among the studies that evaluated the microbiota modula- tion, seven used probiotics; 24 used prebiotics, and five studies were performed using food. After dietary mani- pulation, the growth of bifidobacteria was obtained in 10 studies, in association with weight reduction, adipogenic effects of diet, intestinal permeability and inflammatory markers. Conclusion: Knowledge on the impact of the micro- biota on metabolic pathways allows to conceive new factors associated with obesity and modulation by prebio- tics and probiotics.
In this sense, the main effect observed was the increase in bifidobacteria, usually accompanied by weight loss and enhancement of parameters related to obesity. Key words: Intestinal microbiota. Pro- biotics. Correspondence: Josefina Bressan. Department of Nutrition and Health. E-mail: jbrm ufv.
Recibido: II Aceptado: VI Palabras clave: Microbiota intestinal. AMP: Adenosine Monophosphate. CD Cluster of Differentiation FOS: Fructooligosaccharides. GOS: Galactooligosaccharides. IL Interleukin Lilacs: Latin American and Caribbean Literature. LPL: Lipoprotein Lipase. LPS: Lipopolysaccharides. Scielo: Scientific Eletronic Library Online. TG: Triglycerides. Symbiosis between a host and the intestinal micro- biota is essential for triggering local and systemic responses favorable to the health of the host.
The intes- tinal microbiota is composed of about trillion bacteria and encompasses more than 1, species. Bazzocchi et al. Search strategy. This study is a literature review of scientific articles containing: i basic research on the relationship between intestinal microbiota and obesity, ii clinical studies about the intestinal microbiota and the modulation by prebiotics, iii clinical studies about the intestinal microbiota and the modulation by probiotics.
MeSH Medical Subject Headings was consulted for guidance in the selection of the descriptors used in the review process. The titles and abstracts of all studies iden- tified by the search on electronic platforms were screened. The full texts of potentially relevant studies were read to note the inclusion criteria. We excluded those studies that did not make reference to the relationship between intestinal microbiota and obesity or modulation by prebiotics and probiotics.
The period considered for inclusion of articles was from to Identification of studies. Figure 1 shows the flowchart for the selection of the articles used in this study. The initial search provided 1, articles. After exclu- sion of the review studies, and duplicated results, articles were separated for the study. The first selection was carried through the reading of the titles, followed by analysis of the abstracts and, finally, the assessment of the full texts and selection.
After this refinement, 61 arti- cles that deal with intestinal microbiota and its rela- tionship with obesity were selected. Twenty-nine experi- mental studies and five experimental trials were analyzed. The remaining articles addressed differences in microbial composition between obese and non-obese patients as well as the mechanisms involved. The search for articles was conducted independently by two researchers, who selected together the works to be included in the study.
The papers selected were organized into two themes: relevance of microbiota to obesity and modulation by prebiotics and probiotics. Sandra Tavares da Silva et al. Step Selection 1: articles. Results and discussion.
Intestinal microbiota and its relation with obesity. The identification of differences in the intestinal microbiota of obese and thin people 1 4 suggests the involvement of microbiota in energy homeostasis and storage of lipids. Germ-free animals, even when subjected to high fat diet, did not present hyperfagic behavior, nor increased adiposity or developed metabolic disorders, such as insulin resistance. In the study conducted by Turnbaugh et al.
The increased expression of genes related to codifica- tion of enzymes which are responsible for the degrada- tion of indigestible polysaccharides would lead obese animals to greater generation of fermentation products, with fewer calories remaining in the feces, compared to thin animals.
After installation of the microbiota, stimulation of detoxifi- cation pathways was observed with altered expression of cytochrome P enzymes, strengthening microbial activity in the process of xenobiotic metabolization. Intestinal microbiota and obesity. The comparison confirmed the reduction of Bacterioidetes in obese people, as observed in animal models; and there was no difference for Firmicutes among the groups.
It was observed, however, a significant increase in Lactobaci- llus in obese. Since this species is widely used in food industry, people should be warned about its possible association with obesity. In the same study, the anorexic patients showed significantly higher concen- tration of Methanobrevibacter smithii suggesting a possible adaptive response to nutrient deprivation.
Besides removing excess H 2 from the intestinal lumen,. In the groups Bacteroides, Clostridium and Staphylococcus, a clear change was observed in the predisposition to greater energy storage and develop- ment of inflammatory processes. LPS are products that degrade the cell wall of gram-negative bacteria that, in large quantities, are transported to the intestinal capi- llaries by a mechanism that depends on the TLR4 receptor Toll-Like Receptor-4 of the intestinal mucosa.
Transported to other tissues by chylomicrons synthe- sized from a high fat diet, LPL stimulate the production of inflammatory cytokines and promote a condition called "metabolic endotoxemia. When endotoxemia was induced by subcutaneous infusion of LPS, fasting glycemia, insulinemia and the body weight, liver and adipose tissue presented similar increase, as observed in the animals that ingested high- fat diet.
Increased inflammatory markers and hepatic triglycerides were also observed. These findings demonstrate that endotoxemia alters inflammatory condition and is related to weight gain and diabetes. It suggests that LPS decrease could be an important stra- tegy in the control of metabolic diseases. FIAF is an inhibitor of lipo- protein lipase LPL , an enzyme that hydrolyzes trigly- cerides and stimulates its storage in adipocytes.
Colo- nization increases LPL activity and lipid storage through FIAF suppression, an essential procedure for the deposition of triglyceride in fat cells mediated by microbiota. Protection against obesity is believed to be related to two independent but complementary mecha-.
Obese individuals, who initially presented predomi- nance of Firmicutes in comparison to Bacteroidetes, altered their microbial profile to an inverse proportion after the intake of low-calorie diets with restriction in carbohydrates or lipids for one year, regardless of the diet 2 1 used. In another study, the replacement of a standard diet by a high-fat diet in mice, led to a reduction of Bacteroidetes and increase of Firmicutes and Proteobacteria, regardless of the presence or absence of obesity, which suggests that a high fat diet, instead of obesity itself, as the main responsible for changes in intestinal microbiota and determines its composition.
Microbiota modulation through prebiotics and probiotics. Due to evidence of the relationship between intes- tinal microbiota and obesity, it is necessary to unders- tand if it is possible to manipulate this microbiota to prevent obesity or contribute to weight reduction. In this sense, studies with animals and humans have been developed using food and compounds with prebiotic and probiotic allegation.
Only two studies with animal models were carried out with food, namely, wheat, artichoke 5 0 and rye. Among the studies that used probiotics, the Lactoba- cillus species were the most explored and presented different results. While the administration of Lactoba- cillus ingluvieie and Lactobacillus increased body weight 4 4 , 4 9 , 5 6 and inflammatory markers in mice, 4 4 doses of Lactobacillus paracasei reduced fat accumulation. This result was explained by the authors as an effect of L.
Table I Experimental studies relevant to the topic of obesity, available at the following databases: Lilacs, SciElo, PubMed and ScienceDirect, virtual library, from to Main objective. Prebiotics, probiotics or others. Resistant starch. Wheat arabinoxylans. Bifidobacterium and total bacteria. Highfat diet. Lipid extract of Sorghum Dietary Fiber Chitin-glucan in fungi.
Various Lactobacillus. Various prebiotics. Lipid reserve. Artichokes FOS. High fat.
Intestinal microbiota; relevance to obesity and modulation by prebiotics and probiotics